Field of the Invention
The present invention generally relates to wireless communications. More specifically, the present invention relates to monopole multi frequency antennas.
Description of the Related Art
In wireless communications systems, there is an ever-increasing demand for higher data throughput and reduced interference that can disrupt data communications. A wireless link in an Institute of Electrical and Electronic Engineers (IEEE) 802.11 network may be susceptible to interference from other access points and stations, other radio transmitting devices, and changes or disturbances in the wireless link environment between an access point and remote receiving node. The interference may degrade the wireless link thereby forcing communication at a lower data rate. The interference may, in some instances, be sufficiently strong as to disrupt the wireless link altogether.
FIG. 1 is a block diagram of a wireless device 100 in communication with one or more remote devices and as is generally known in the art. While not shown, the wireless device 100 of FIG. 1 includes antenna elements and a radio frequency (RF) transmitter and/or a receiver, which may operate using the 802.11 protocol. The wireless device 100 of FIG. 1 may be encompassed in a set-top box, a laptop computer, a television, a Personal Computer Memory Card International Association (PCMCIA) card, a remote control, a mobile telephone or smart phone, a handheld gaming device, a remote terminal, or other mobile device.
In one particular example, the wireless device 100 may be a handheld device that receives input through an input mechanism configured to be used by a user. The wireless device 100 may process the input and generate a corresponding RF signal, as may be appropriate. The generated RF signal may then be transmitted to one or more receiving nodes 110-140 via wireless links. Nodes 120-140 may receive data, transmit data, or transmit and receive data (i.e., a transceiver).
Wireless device 100 may also be an access point for communicating with one or more remote receiving nodes over a wireless link as might occur in an 802.11 wireless network. The wireless device 100 may receive data as a part of a data signal from a router connected to the Internet (not shown) or a wired network. The wireless device 100 may then convert and wirelessly transmit the data to one or more remote receiving nodes (e.g., receiving nodes 110-140). The wireless device 100 may also receive a wireless transmission of data from one or more of nodes 110-140, convert the received data, and allow for transmission of that converted data over the Internet via the aforementioned router or some other wired device. The wireless device 100 may also form a part of a wireless local area network (LAN) that allows for communications among two or more of nodes 110-140.
For example, node 110 may be a mobile device with Wi-Fi capability. Node 110 (mobile device) may communicate with node 120, which may be a laptop computer including a Wi-Fi card or wireless chipset. Communications by and between node 110 and node 120 may be routed through the wireless device 100, which creates the wireless LAN environment through the emission of RF and 802.11 compliant signals.
Efficient design of wireless device 100 is important to provide a competitive product in the market place. It is important to provide a wireless device 100 with a small footprint that can be utilized in different environments. Wireless device 100 may have dipole antenna elements built into the circuit board or manually mounted to the wireless device. When mounted manually, matching antenna elements are attached to opposing surfaces of the circuit board and typically soldered although those elements may be attached by other means.
A monopole antenna includes only a single radiating element and is coupled to a ground plane of a transmitter. The monopole radiation reflects from the ground plane to provide radiation in a dipole antenna radiation pattern. Dipole antenna elements may provide beam steering RF signals but are more costly to manufacture than monopole antennas. There is a need for an improved beam steering antenna apparatus for use in wireless devices.